Silicon Carbide (SiC) Powder: Cov khoom siv, kev siv ua haujlwm

Rau cov neeg yuav khoom thoob ntiaj teb thiab cov thawj tswj kev yuav khoom, kev nkag siab txog cov nuances ntawm silicon carbide hmoov tsis yog ib qho kev xav tau - nws yog qhov tsim nyog sib tw. Txawm hais tias nws yog siv los ua deoxidizer hauv steelmaking, kev ua haujlwm siab abrasive, lossis ib qho tseem ceeb hauv lub tsheb fais fab (EV) hluav taws xob hluav taws xob, SiC muaj kev sib xyaw tshwj xeeb ntawm hardness, thermal conductivity, thiab tshuaj stability.

Silicon Carbide (SiC) yog dab tsi?

Silicon carbide yog cov khoom siv hluav taws xob sib xyaw ua ke ntawm silicon thiab carbon. Nyob rau hauv cov xwm, nws yog tshwj xeeb tshaj yog tsis tshua muaj, pom tsuas yog nyob rau hauv ib tug kab nyob rau hauv tej yam meteorites thiab corundum deposits. Yog li ntawd, yuav luag tag nrho cov silicon carbide siv nyob rau hauv kev lag luam yog synthetically tsim.

Crystal Structure

SiC yog qhov tshwj xeeb vim nws nthuav tawm polymorphism, txhais tau tias nws tuaj yeem muaj nyob hauv ntau dua 250 cov ntaub ntawv crystalline. Feem ntau cov qauv muaj xws li:

Alpha Silicon Carbide (α-SiC): Feem ntau polymorph, tus yam ntxwv los ntawm cov qauv siv lead ua hexagonal. Nws ruaj khov ntawm qhov kub siab tshaj 1700 ° C.

Beta Silicon Carbide (β-SiC): Daim ntawv no muaj cov qauv siv lead ua cubic (zoo ib yam li pob zeb diamond) thiab tsim los ntawm qhov kub thiab txias hauv qab 1700 ° C.

Ntsiab Physical and Chemical Properties

Vim li cas SiC hmoov thiaj nrhiav tom qab? Nws cov kev ntsuas kev ua tau zoo yog unparalleled:

Hnyav hnyav: Nrog Mohs hardness ntawm 9.0 txog 9.5, nws tsuas yog thib ob rau pob zeb diamond thiab boron carbide.

High Thermal Conductivity: SiC dissipates cua sov sai dua li cov hlau feem ntau, ua rau nws zoo tagnrho rau qhov chaw kub kub.

Tsawg Thermal Expansion: Nws tiv thaiv warping los yog tawg nyob rau hauv tam sim ntawd kub hloov (zoo heev thermal shock kuj).

Chemical Inertness: Nws tiv taus corrosion los ntawm acids, alkalis, thiab molten ntsev, txawm nyob rau qhov kub siab.

Semiconducting Properties: Tsis zoo li ntau lwm yam abrasives, SiC yog qhov dav-bandgap semiconductor, uas yog hloov pauv lub zog hluav taws xob kev lag luam.

Txoj Kev Tsim Khoom: Acheson Method thiab Tshaj

Kev tsim khoom ntawm high-puritysilicon carbide hmoovyog ib lub peev-intensive thiab zog-hnyav txheej txheem.

Cov txheej txheem Acheson

Tsim los ntawm Edward Goodrich Acheson hauv 1891, qhov no tseem yog thawj txoj hauv kev rau kev tsim khoom loj.

Raw Khoom: High-purity silica xuab zeb (SiO2) thiab roj av coke (C) yog tov. Qee zaum, sawdust thiab ntsev ntxiv los tswj cov porosity thiab tshem tawm impurities.

Cov Hluav Taws Xob Hluav Taws Xob: Cov sib tov yog muab tso rau hauv lub qhov cub ua haujlwm. Ib qho hluav taws xob tam sim no tau dhau los ntawm cov tub ntxhais graphite, ua kom sov qhov sib xyaw ib puag ncig rau qhov kub ntawm 1,700 ° C thiab 2,500 ° C.

Tshuaj Reaction: SiO2 + 3C → SiC + 2CO tshwm sim.

Kev Sau: Thaum lub qhov cub txias, qhov loj "cylindrical" loj ntawm SiC muaju yog tsim. Cov tub ntxhais muaj qhov siab tshaj plaws purity (Green SiC), thaum cov txheej txheej sab nrauv tawm los Black SiC.

Kev ua rau hmoov

Thaum cov crude crystals raug sau, lawv tau mus rau ntau theem ntawm kev ua:

Crushing & Milling: Siv lub puab tsaig crushers, rauj mills, los yog pob mills kom txo tau cov muaju rau hmoov.

Kev muab qhab nia (Sizing): Siv cov ntxaij vab tshaus vibrating lossis cov khoom siv huab cua kom ntseeg tau tias cov hmoov ua tau raws li qhov loj me me (piv txwv li, FEPA, JIS, lossis ANSI cov qauv).

Acid Ntxuav & Purification: Txhawm rau tshem tawm cov hlau seem, dawb silicon, lossis carbon, cov hmoov feem ntau raug kho nrog tshuaj kom ncav cuag purity theem ntawm 98% mus rau 99.9%.

Dub vs Green Silicon Carbide: Nkag siab qhov txawv

Nyob rau hauv lub ntiaj teb no kev ua lag luam, SiC hmoov yog feem ntau categorized los ntawm nws cov xim, uas qhia txog nws purity thiab npaj siv.

Dub Silicon Carbide (Black SiC)

Dub SiC muaj kwv yees li 95% mus rau 98% SiC. Nws cov xim tsaus yog vim muaj cov kab ntau ntawm cov hlau thiab carbon impurities.

Yam ntxwv: me ntsis tougher tab sis nkig tsawg dua ntsuab SiC.

Qhov zoo tshaj plaws rau: Sib tsoo cov ntaub ntawv muaj zog tensile xws li cam khwb cia hlau, cov hlau tsis muaj hlau (tooj liab, txhuas), thiab cov khoom tsis yog xim hlau (pob zeb, roj hmab, ntoo). Nws tseem yog thawj qhov kev xaiv rau metallurgical deoxidization.

Ntsuab Silicon Carbide (Green SiC)

Ntsuab SiC yog qhov ntau dua-purity variant, feem ntau tshaj 99% SiC cov ntsiab lus.

Cov yam ntxwv: siab hardness thiab superior txiav zog piv rau dub SiC.

Qhov zoo tshaj plaws rau: Precision sib tsoo cov ntaub ntawv nyuaj thiab nkig xws li tungsten carbide, optical iav, ceramics, thiab semiconductor wafers.

Primary Industrial Applications

Metallurgy thiab Steelmaking

Hauv kev lag luam metallurgical, SiC hmoov ua haujlwm ua lub zog deoxidizer thiab roj qhov chaw hauv cupolas thiab hluav taws xob arc rauv.

Cov txiaj ntsig: Nws txhim kho cov dej ntws ntawm cov hlau molten, txhim kho cov silicon thiab cov pa roj carbon rov qab, thiab txo cov kev siv zog tag nrho ntawm cov txheej txheem melting.

Cam khwb cia hlau ntau lawm: Nws txhawb kev tsim cov graphite flakes, ua rau zoo dua grey thiab ductile hlau castings.

Abrasives thiab Surface Finishing

Qhov no yog kab tias feem ntau siv SiC hmoov.

Bonded Abrasives: Siv los tsim kev sib tsoo log thiab txiav discs.

Coated Abrasives: Siv rau hauv cov ntawv xuab zeb thiab polishing siv.

Lapping & Polishing: Zoo SiC hmoov yog siv rau hauv "slurries" rau precision lapping ntawm li qub, iav, thiab semiconductor substrates.

Refractories thiab Ceramics

Vim nws qhov siab melting point (nws sublimes nyob ib ncig ntawm 2,700 ° C) thiab qis thermal expansion, SiC yog cov khoom tseem ceeb tshaj plaws.

Kiln Furniture: SiC daim hlau thiab kab teeb yog siv nyob rau hauv ceramic kilns vim lawv tsis deform nyob rau hauv hnyav loads ntawm huab cua kub.

Technical Ceramics: Siv rau hauv cov tsho tiv thaiv mos txwv, foob nplhaib rau cov twj, thiab tsheb nres discs.

Advanced Electronics (Lub SiC Revolution)

Lub xyoo pua 21st tau pom qhov nce hauv SiC qhov kev thov rau kev lag luam semiconductor.

Cov Khoom Siv Hluav Taws Xob: SiC-raws li MOSFETs thiab diodes muaj txiaj ntsig zoo dua li cov khoom siv silicon ib txwm muaj.Lawv yog qhov tseem ceeb rau cov khoom siv ceev ceev thiab cov inverters hauv Hluav Taws Xob (EVs).

5G Infrastructure: SiC ua haujlwm raws li lub substrate rau Gallium Nitride (GaN) ntawm SiC cov khoom siv, uas lub zog muaj zog 5G hauv paus chaw nres tsheb.

Ntiaj teb no Quality Standards for SiC Powder

Thaum muab khoomSiC hmoovthoob ntiaj teb, cov neeg yuav khoom yuav tsum tau mus rau ntau yam kev muab qhab nia:

FEPA (Federation of European Producers of Abrasives): Siv cov "F" (rau kev sib koom ua ke abrasives) thiab "P" (rau coated abrasives) prefixes (piv txwv li, F240, P1200).

JIS (Japanese Industrial Standard): Feem ntau nyob rau hauv Asian lag luam (piv txwv li, #3000).

ANSI (American National Standards Institute): Txheem rau North American lag luam.

Purity Levels Matter:

Metallurgical Qib: 88% -95% SiC.

Abrasive Qib: 96% -98.5% SiC.

High Purity / Ceramic Qib: 99% SiC.

Silicon carbide hmoov yog ntau tshaj li qhov yooj yim abrasive.Nws yog cov khoom siv thev naus laus zis uas txuas qhov sib txawv ntawm kev lag luam hnyav thiab lub neej yav tom ntej ntawm lub zog huv.Los ntawm kev nkag siab nws cov qib, cov txheej txheem tsim khoom, thiab cov ntawv thov, cov kws tshaj lij hlau thiab cov kws tshaj lij tuaj yeem xyuas kom lawv xaiv cov khoom tsim nyog los txhim kho lawv cov haujlwm thiab cov khoom zoo.